There is no Bluesky share button on Substack, but there's a button to share to Xitter. Weird.
If you click on the link to my newsletter I'm sure it'll tell Substack that they get a chunk of traffic from Bluesky & might perhaps take this place more seriously. ;-) https://open.substack.com/pub/documentally/p/one-thing-is-many-511?r=h8a8&utm_campaign=post&utm_medium=web&showWelcomeOnShare=true